This invention relates to method of and apparatus for feeding randomly received items and for placing these items, one at a time, on apparatus, such as a flight conveyor or packaging machine, which cycles continuously at a steady rate.
In certain packaging or other operations, the items to be packaged are delivered to the packaging apparatus at an average rate, for example, 60 items per minute, with slight spacing irregularities between successive items. Because these items are randomly received, (i.e., they are not exactly equally spaced from one another) and because the rate at which they are delivered is not necessarily a fixed ratio relative to the speed at which the packaging apparatus is operated (i.e., the item delivery system and the packaging apparatus may not share a common drive), the spacing variations between the items and/or the differences between the delivery rate of the items and cycling rate of the apparatus causes these rates to be periodically in and out of phase with one another. This difference in phase would result in jamming of the packaging apparatus. Thus, there is a need to pace the feeding and placement of the items to be packaged on the continuously operating apparatus so as to avoid jamming or other malfunctions.
In prior feeding or pacing systems, it was conventional for either the feed or pacing system or the packaging apparatus to be operated at a speed significantly faster than the rate at which items were delivered so that each item could be stopped at a holding station, and then fed forward onto the packaging apparatus in timed relation to the packaging apparatus. This, however, required that either the pacing system or the packaging apparatus be continuously operated at a speed significantly faster than the rate at which the items were received and that the pacing system or the packaging apparatus be operated through several cycles without wrapping a package. Thus, the pacing system or the packaging apparatus was necessarily subjected to higher accelerations and loads due to the increased speed at which it operated and the wear and tear on the packaging machine was disproportionate to the number of items packaged.
In packaging certain items, such as stacks of loose paper sheets (reams of paper) received from a sheeter or the like, other problems are encountered in handling the stacks of loose sheets of paper prior to their being wrapped. For example, the loose sheets are easily damaged and the sheets tend to shift when the stacks are accelerated or decelerated.